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<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script>
			window.onload = function(){
				console.log("定时器启动前...")
				var start = Date.now();
				setInterval(function(){
					console.log("定时器执行了, " + (Date.now() - start))
				}, 200);
				
				for (var i = 0; i < 1000000000; i++) {
				}
			}
		</script>
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	<body>
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</html>
